Hi mummies and daddies, how do you teach your lo not to throw things off the high chair or cot?

How old is your little one? Mine is one and when she does it I raise my finger, give her the look and walk out of the room and close the door and I sit on the floor outside her room, while she cries and screams a hissy fit. Once she has calmed down I go back in, hug her and kiss her and firmly say no while pointing to the Toy. The next time she does it, I do the same. 3 days later she stopped doing it as she knew mummy meant business.